However, it *can* be "pressed into service" longer if needed. I have an outdoor Fern
that's been in the 5-1-1 for two years now, and the mix has not compacted. I also have
a few Maples and Buckeyes in the 5-1-1 that are going into their second year now.

Much of this depends upon how composted your bark is. I use uncomposted bark, so that buys
some extra time in the bucket, as it were. Highly composted bark will breakdown much
more rapidly, obviously.

Josh

I will say though that with the gritty and 5:1:1 mixes, tight roots are usually a growth/vitality limiting factor BEFORE soil collapse is an issue, which sort of makes the answer to the question moot. I'm not being smart, at all, just trying to add some perspective. ;-)

AL

I would like to grow vegetable transplants in 3 and 6-packs according to organic standards in a greenhouse using your 5.1.1 mix as pine fines are readily available to me. I have 2 questions:

1) Would you recommend substituting coconut coir for the peat?
2) Can you recommend an organic slow release fertilizer that could be used in this mix so that I would not have to use a liquid solution everytime I watered (the small containers will have to be watered at least daily, sometimes multiple times).

1) Probably not. Coir's main advantage is its wetability, but it often has salinity issues as well as an extremely high K content. Its high pH also precludes using lime as a Ca/Mg source. Peat has none of these issues - and if you allow it to dry down to the point that rewetability comes to play as an issue - you already have problems anyway because you've let the medium dry down too much.

2) I can't help much with a fertilizer suggestion for you because I left organic nutritional sources behind a long time ago; that, because I found soluble fertilizers so much easier and more effective. I DO understand and respect anyone's wish to maintain an all organic ideology, but if there is a chink in your resolve, we should talk about it a little. Not wanting to bug you or offend, I'll leave initiating that conversation up to you. ;-)

AL

Can you define "soluble fertilizers" for me? Is that the opposite of something granular included in the mix in order to be able to water with plain water since the cell packs dry out so quickly. It seems that watering with a liquid fertilizer solution every time the cell packs dry out would be impractical - very different from watering large containers.

Fertilizers that supply their nutrients locked in organic molecules need to rely on soil organisms to cleave hydrocarbon chains and 'unlock' the nutrients by breaking them down into elemental forms. The problem with this is, the microorganism populations you must rely on are extremely variable in containers, being greatly affected by a number of factors, among them temperature, moisture and air volumes in the soil, pH, fertility, soil type ..... There is no way of telling if the N in the fertilizer that derives its N from feather or horn meal will give up its N today or a month from today.

There is no need to fertilize every time you water when using soluble fertilizers. It's a good strategy if you have only a few plants, but not requisite. I fertilize (usually) weekly in the summer, and every time I water in the winter.

Some granular fertilizers, like MG and FP, are soluble. Some granular fertilizers, like most granular lawn or garden fertilizers are 'slow-release' products because they are only marginally soluble. Most 'organic' fertilizers that get their N from organic sources are also slow-release because of the length of time it takes them to break down into elemental forms plants can assimilate.

When it's all said & done, plants 'eat' salts as the building blocks they use to make their own food and keep their metabolism humming. The nutrients they take up are in the same form, whether they came from a dead fish, blood/hoof/horn meal, or from a plastic container of Miracle-Gro. They don't know and don't care where their nutrients come from, as long as they get them.

Finally, I believe strongly in the adage "feed the soil not the plant ....... in my garden - but when it comes to container culture, what works best in the garden is often best left there. Container culture is much closer to hydroponics than growing in the earth, so it's not a big stretch to allow that it might take a different set of tools to achieve the best results.

There is a LOT of disagreement about what is and isn't acceptable insofar as fertilizers are concerned if you wish to be considered an 'organic' grower. I don't get involved with the politics because I don't care too much about it (bigger things to worry about), and I'm much closer to being a slave to results than ideology. You could probably get recommendations from the crowd at the organic gardening forum, but it's rare that there is ever much of a consensus when it comes to fertilizing containerized plants. Maybe fish emulsion would suit the application?

AL

AL

Al

Yes. To hold these populations of microbs to break down the organics you need soil that retains a good amount of water. And we all know the more the drainage the faster the plant grows. This is why I always have seen more results using synthetic fertilizer in potts because you can have extreme drainage not to worry about the colinies of microbs washing out.